I. Field of the Invention
This invention relates to depressible, reflective pavement markers for delineating roadways and, in particular, to a resilient pavement marker which is resistant to rotation from external forces yet ensures depression and return of the reflector assembly above the road surface.
II. Description of the Prior Art
The benefits of roadway lane markers to delineate traffic paths for drivers are unquestioned. Pavement markers are more desirable than the usual painted dividing lines because such reflective markers are more visible to a driver over a greater distance and will function better in many instances where painted traffic lines are seen by a driver only with difficulty such as on wet roadways, snow covered roadways or in fog. The prior known markers typically are available in two forms--the surface mount marker secured directly to the roadway surface or an imbedded marker positioned within a preformed hole in the roadway. Surface mount markers are more widely utilized in warmer climates where the markers would not be subject to the shearing effects of a snow plow. The structural integrity of imbedded markers makes them more suitable for roadways subject to various weather conditions.
In order to withstand the forces of oncoming snowplows and vehicle tires, a variety of retractable road markers have been developed. The retractable marker, although it protrudes above the road surface, may be depressed by the blow of a snowplow blade or vehicle tire. Typically, a beveled upper surface formed on the reflector protrusion provides an inclined plane across which the blade or tire rides deflecting the protruding portion of the marker downwardly into its housing. Such depressible markers have incorporated spring assemblies for biasing the reflector, flexible diaphragms which carry the reflector or foam rubber cells facilitating depression of the reflector. However, the effects of dirt and grime, freezing and thawing, snow, rainwater and the forces associated with the road traffic all detrimentally effect the prior known depressible reflectors. Over time reflectors which depend upon exposed rubber components deteriorate to failure. Still other reflectors cannot withstand the torquing effect of the snow plow blades engaging the reflector.
A significant disadvantage of prior known pavement markers is encountered when the reflector becomes damaged requiring repair. The roadway markers used in the past require removal of the entire assembly from the roadway or, at a minimum, disassembly of the housing in order to effect a repair as simple as replacing a shattered reflective lens.